Symptoms

Since the upgrade to Blackpearl 4.6.9 at 04/22/2015, Workflows immediately run into the error state on production when hitting the first activity.
Log entries Point into the wrong direction, stating the user has no rights to start the process - this has not changed since the update and all rights are in place.
The log entry telling that no credentials are cached is wrong, too.
 

Diagnoses

The permissions error in the logs are very vague.
With my experience this should be an issue in the Identities.Identities tables.
 

Resolution

-Refreshing the Identities.identities table for the K2 service account
-Removing/setting the SAP credentials for the K@ service account
Fixed the issue.